diff --git a/python/setup.py b/python/setup.py
index eda25749c6d9dac5ccad09f13811f28fac4a2e09..e109ee75fe68e5c2d770d7c9bceb7d46775af303 100755
--- a/python/setup.py
+++ b/python/setup.py
@@ -108,6 +108,7 @@ if __name__ == '__main__':
           'google.protobuf.internal.input_stream',
           'google.protobuf.internal.message_listener',
           'google.protobuf.internal.output_stream',
+          'google.protobuf.internal.type_checkers',
           'google.protobuf.internal.wire_format',
           'google.protobuf.descriptor',
           'google.protobuf.descriptor_pb2',
@@ -115,7 +116,7 @@ if __name__ == '__main__':
           'google.protobuf.reflection',
           'google.protobuf.service',
           'google.protobuf.service_reflection',
-          'google.protobuf.text_format'],
+          'google.protobuf.text_format' ],
         url = 'http://code.google.com/p/protobuf/',
         maintainer = maintainer_email,
         maintainer_email = 'protobuf@googlegroups.com',